THIS IS A EXPERIMENTAL DETECTION
This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.
The following analytic detects suspicious processes on systems labeled as web servers. This detection is made by a Splunk query that searches for specific process names that might indicate malicious activity. These suspicious processes include "whoami", "ping", "iptables", "wget", "service", and "curl". Uses the Splunk data model "Endpoint.Processes" and filters the results to only include systems categorized as web servers. This detection is important because it indicates unauthorized or malicious activity on web servers since these processes are commonly used by attackers to perform reconnaissance, establish persistence, or exfiltrate data from compromised systems. The impact of such an attack can be significant, ranging from data theft to the deployment of additional malicious payloads, potentially leading to ransomware or other damaging outcomes. False positives might occur since the legitimate use of these processes on web servers can trigger the analytic. Next steps include triaging and investigating to determine the legitimacy of the activity. Also, review the source and command of the suspicious process. You must also examine any relevant on-disk artifacts and look for concurrent processes to identify the source of the attack.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2019-04-01
- Author: David Dorsey, Splunk
- ID: ec3b7601-689a-4463-94e0-c9f45638efb9
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.dest_category="web_server" AND (Processes.process="*whoami*" OR Processes.process="*ping*" OR Processes.process="*iptables*" OR Processes.process="*wget*" OR Processes.process="*service*" OR Processes.process="*curl*") by Processes.process Processes.process_name, Processes.dest Processes.user | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `web_servers_executing_suspicious_processes_filter`
The SPL above uses the following Macros:
web_servers_executing_suspicious_processes_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the
Processes node of the
Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known False Positives
Some of these processes may be used legitimately on web servers during maintenance or other administrative tasks.
Associated Analytic Story
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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